When creating JPG Derivates based on greayscale input JPG Data and scale them for example from
2156x3308 pixel or even 7447x11422
to
1042x1600 pixel
the luminance of the down scaled images increases significantly (and visible!)
This is unintended behavior.
It is required to keep the same luminance as good as possible at scale time, otherwise scaled derivates are not usable since the text becomes almost unreadable in viewers like DFG-Viewer that utilize them.
Desccription
When creating JPG Derivates based on greayscale input JPG Data and scale them for example from 2156x3308 pixel or even 7447x11422 to 1042x1600 pixel the luminance of the down scaled images increases significantly (and visible!)
This is unintended behavior. It is required to keep the same luminance as good as possible at scale time, otherwise scaled derivates are not usable since the text becomes almost unreadable in viewers like DFG-Viewer that utilize them.